function [rmin rmax cmin cmax] = bboxletter(img, startColumn)
    [row col] = size(img);
    rmin = -1;
    rmax = -1;
    cmin = -1;
    cmax = -1;
    %Find first text column
    cmin = findFirstAfter( img, 1, row, startColumn, col, startColumn, 1, 0 );
    if cmin == -1 
        return;
    end
    %Find first background column starting from ftc
    cmax = findFirstAfter( img, 1, row, startColumn, col, cmin + 1, 1, 1 ) - 1;
    if cmax <= 0
        cmax = col;
    end
    %Find first text row between cmin and cmax
    rmin = findFirstAfter( img, 1, row, cmin, cmax, 1, 2, 0 );
    if rmin == -1 
        return;
    end
    %Find first background row between cmin and cmax and starting from rmin
    rmax = findFirstAfter( img, 1, row, cmin, cmax, rmin + 1 , 2, 1 );
    if rmax <= 0
        rmax = row;
    end
end
